Analogue and digital signals-P6

(notes taken from the CGP revision guides)

• Analogue signals vary but digital's either on or off.
• The amplitude or frequency of an analgue signal vary continuously.
• An analogue signal can take any value in a particular range.
• Dimmer switches, thermometers, speedometers and old-fashioned watches are all analogue devices.
• Digital signals can only take two values - they're made up of 'pulses'.
• A digital receiver will decode these pulses to get a copy of the orignal signal.
• On/off switches and the displays on digital clocks and meters are all digital devices.
• Signals have to be amplified.
• Both digital and analogue signals weaken as they travel, so they may nee to…